I had a bizarre experience with Velveeta this past weekend and was hoping you all could help me out.

I bought a block of Velveeta and some Rotel canned tomatoes to make a queso dip. I microwaved the dip for about 8 minutes total (taking out after 5 to stir.) After the 8 minutes were up, I started stirring the queso and noticed that the cheese was still clumpy.

So, I stuck the queso back in the microwave for four more minutes and when I took it out, it was worse than before.

This has never happened before, usually when it gets clumpy, you can just throw it in to the microwave for a little while longer and it comes out nice.

What happened here? Do some foods become clumpy when they are cooked too long? Could the Velveeta have been bad? I've made this several times, and I don't think I did anything different here.

Kraft has changed the velvetta. it is now crap instead of the cheese we all grew up with and love. Look at all the complaints on the web. Kraft is trying to save a little money and screwed up their product. Kraft will not admit it, but they should fire the person that is responsible and go back to the old product we love. I will never buy another box of Velvetta.
This happened at the end of of 2012 and all the velvetta now will not melt, the oil seperates out of it and it makes a gooey mess.